Forum OpenACS Q&A: Re: Kernel Parameter: PerformanceModeP and PermissionCache

Nima, turn on developer support including looking at the DB and post the total time, the number of DB queries and the time needed for the execution of the DB queries.

If you have lots of DB queries and can't memoize them, go for a seperate webserver (something you might want to do anyway, the current one should be more than fine for the database, if you have a fast RAID configuration). How large is your database anyway, could you run it completely out of RAM (if you have the whole server for postgres, allow PG to grab more RAM).

If the total time is large but your DB query numbers are low, then you should get a faster processor or a second & third webserver as this hints that AOLserver is really busy.

Sadly you will always have to provide Hardware assuming the "worst" case, but it has not to be dedicated. What you could do is have a second server that runs a non critical system provide the AOLserver. And yes, I'm usually a person that is highly in favour of splitting up database and webserver.